There are numerous types of endless power transmission belts in present use which are made primarily of elastomeric materials, known as V-ribbed belts. These belts have longitudinal ribs in the compression section as an integral part of the belt, and the ribs may be V-shaped or in the form of truncated Vees. The fabrication of such belts is usually complex and expensive, and there is a constant effort to find new ways of manufacturing which are simpler and less costly.
Some of the most recent methods of making belts of this type are disclosed in U.S. Pat. Nos. 3,822,516; 3,839,116; 3,891,405; and 3,981,206. The use of such belts is illustrated by U.S. Pat. Nos. 3,951,006; 4,028,995; and 4,031,761.
The present invention is an improvement over the prior art, particularly with respect to the number of fabricating steps necessary to produce a V-ribbed belt. According to the present invention, a belt sleeve is fabricated by assembling the various components in a conventional manner on a drum. However, instead of using curing devices such as shown in U.S. Pat. Nos. 3,839,116 and 3,981,206, the curing is accomplished on a curing mechanism known as "Rotocure", which comprises a heated cylinder and an endless band passing around the cylinder. Such a mechanism is shown, for example, in U.S. Pat. No. 2,039,271.
While it is known to treat a complete sleeve of material in order to form it into individual belts, for example as outlined in U.S. Pat. Nos. 3,477,895 and 3,565,984, the present invention is an improvement over the teaching of these patents, in that sufficient rubber is employed in fabricating the belt sleeve to completely fill the grooved roller during the forming process so that the load-carrying cord is continuous across the sleeve. The load-carrying cord, according to the present invention, is not cut into individual belt widths and is not compressed into the body of the belt, which would result in distortion.
A further feature of the method of this invention is that belts having polyester load-carrying cord are formed completely on the vulcanizing apparatus and do not require subsequent stabilization on a separate apparatus as is disclosed in U.S. Pat. No. 3,761,558.
It is therefore an object of the present invention to provide an improved process for producing a V-ribbed belt.
Other objects, aspects and several advantages of the present invention will be apparent to those skilled in the art from a reading of the following detailed description, as well as the appended claims.